$ A = \left[\begin{array}{rrr}2 & 3 & 1 \\ 7 & 5 & 5\end{array}\right]$ What is $ A^{T}$ ?
Answer: To find the transpose, swap the rows and columns. $ A^{T}$ = $\left[\begin{array}{rr}2 & 7 \\ 3 & 5 \\ 1 & 5\end{array}\right]$